The Four Main Metal Coating Types

Generally, the overarching goal of metal coating is to protect ferrous metals from corrosion and improve the appearance of the material. There are many different metal coating types, though, so it can be difficult to decipher which treatment may have been used on different products.

Anodising

Anodising is the act of using an electric current to increase the thickness of the aluminium oxide layer on the outside aluminium, with the original layer forming as the metal reacts with the air. While this process is most common with aluminium, it is also used with titanium and zinc. This additional layer of oxidation protects the aluminium from corrosion and presents a better surface of adhesion for paints and other coatings.

Ferrous metals cannot be anodised, however, because they are susceptible to rusting and the protective layer would consequently flake off with the rust.

Galvanising

When a layer of zinc is added to the surface of steel or iron, this process is called galvanisation. Hot-dip galvanisation is the most common form of the process and is when steel is dipped into a molten bath of zinc.

The molten zinc adheres immediately to the solid metal – reacting to the oxygen in the air – and therefore adds a layer of zinc oxide to protect against corrosion.

Electroplating

An electric current is used to adhere a solution of cadmium and chromium to a metal in electroplating, and a common example is nickel plating. A consistent coverage is difficult to achieve, though.

Electroplating provides a surface with a pleasing appearance that is resistant to corrosion.

Powder Coating

A dry powder is applied electrostatically and then cured at over 200 degrees Fahrenheit to powder coat a metal. This process provides a consistent appearance and is also more environmentally-friendly than painting due to there being no solvents involved.

Powder coating also allows for unlimited colour options.

Widely Applicable and Very Effective

The metal coating types we have mentioned today are applicable in a variety of environments – throughout domestic manufacturing and industrial construction – which is why they are essential and cover an array of different metals.

Shirley Industrial Painters & Decorators Limited

Here at Shirley Industrial Painters & Decorators Limited, we provide a range of protective coatings for industrial and commercial customers. If you’d like to hear more, please contact us by calling 03333 660 408 or filling out our contact form.